Strange AH WG portal

[Yasik]

look
The Wide Gate
This is the northern gate of Aisholm, a small human settlement in the
frozen continent of Thule. A set of wide double gates opens in the wall,
and there is a building to the south. The street is unpaved, its loosely
packed clay as naked as when the humans first arrived to Thule. The whole
town must turn into a mudhole when the snow melts. A high walkway runs
the length of the stockade.
Exits: North East West
A stalk of celery grows in a patch of well-kept soil. [2]
A bright orange carrot top can just barely be seen growing in some soil.
A magical spring gurgles out fresh water. [2]
A tomato vine grows out of a patch of soil, bearing a single ripe tomato.
A soiled sheet from some notebook shifts here in the wind.
A hastily wrapped brown parcel lies here on the floor.
AN OPEN PORTAL IS HERE!
Fallen Looking for 1x Chrysoprase is sleeping here.
A frost giantess is guarding the gate.
A frost giant is guarding the gate.

<209hp 197ma 62mv> [+0] AC: 4.5 EXP: 1717582 COINS: 76082 [raining] [Aisholm Town]
enter portal
There are no visible portals here.

<210hp 200ma 63mv> [+0] AC: 4.5 EXP: 1717582 COINS: 76082 [raining] [Aisholm Town]
look portal
There's no portal to look through here!

=====

How's that possible?

[Tuck]

Confirmed.

Cursed and invised

[Yasik]

I had Detect Invisibility on.

[Tuck]

silly yasik,
i invised it.
and cursed.

dork

[Yasik]

That was not the question. The question is why it is even there, who opened it and why I cannot look through it or enter it, and why it persists so long - few days already.

[Tuck]

it's magic